ATK Supports First Launch of Delta IV Medium-Plus Vehicle Featuring Four Motors

20:23 GMT, December 7, 2009 MINNEAPOLIS | Alliant Techsystems' (NYSE: ATK) composite, propulsion and spacecraft technologies supported the successful launch of a United Launch Alliance Delta IV rocket from Space Launch Complex 37 at Cape Canaveral Air Force Station, Fla., carrying the Wideband Global SATCOM (WGS-3) for the U.S. Air Force.

This was the first time the Delta IV medium-plus rocket featured four ATK 60-inch-diameter Graphite Epoxy Motors (GEM). The composite cases for the GEM motors were fabricated at the ATK Clearfield, Utah facility. The 70-foot-long motors were mounted in pairs on opposing sides of the rocket, with one fixed and one vectorable nozzle per side, and provided the auxiliary lift-off capability for the Delta IV medium plus configuration rocket. The GEM 60s burned for 90 seconds and provided 1,120,000 pounds of thrust to deliver the WGS satellite to its determined orbit.

ATK also designed and produced the nozzle for the Delta IV's RS-68 engine. The Pratt & Whitney Rocketdyne-built RS-68 is the largest hydrogen-fueled engine in the world. ATK also designed and produced the nozzle's thermal protection material, which is capable of shielding the nozzle from the extreme heat of launch when external temperatures can exceed 4,000 degrees F. The nozzle is manufactured at ATK's Promontory, Utah facility.

ATK supplied 10 key composite structures for the Delta IV medium plus launch vehicle: the interstage that provides the interface between the Common Booster Core (CBC) and the cryogenic second stage, a centerbody that integrates the liquid oxygen (LO2) and liquid hydrogen (LH2) tanks, a thermal shield that protects the RS-68 engine during ignition and flight, one LO2 skirt, and one aeroskirt. The payload is encapsulated by ATK's 5-meter diameter composite payload fairing, along with required hardware for payload integration including a nose cap, x-panels, payload attach fitting, and payload attach fitting diaphragm.

The composite structures are five meters in diameter and range from one to more than 15 meters in length. They are produced using hand layup, machining and inspection techniques at the company's manufacturing facility in Iuka, Miss.

ATK provided key subsystem and component technologies for the successful launch of the WGS-3 satellite. ATK's Commerce California facility provided the propellant tank for the Delta IV upper stage roll control system. Additionally, ATK Space Structures based in San Diego manufactured the payload module and the solar array substrates panels.

WGS-3, the third satellite of the series, will provide high-capacity X-band and Ka-band communications support to the U.S. and allied air forces in military operations across the world. WGS-1 has been in operation over the Pacific since April 2008, and WGS-2 has been operating over the Middle East since August 2009.